1. Cardiothoracic Surgery Department, New Cross Hospital, Royal Wolverhampton NHS Trust, UK
2. Health Economics Unit, University of Birmingham, UK
3. Intensive Care Department, New Cross Hospital, Royal Wolverhampton NHS Trust, UK
4. Department of Health Services Research & Policy, London School of Hygiene and Tropical Medicine, UK
5. Cardiothoracic Anaesthesiology Department, New Cross Hospital, Royal Wolverhampton NHS Trust, UK